You are correct; you require one (or two) 4-pin cables. I bought mine through Amazon USA (see here: Amazon.com: USB A Female to 1 X 4 Pin Internal USB Connector 1.25 mm Pitch). Unfortunately, I cannot see this product on Amazon's UK site, so likely you will need to contact the vendor, Micro SATA Cables, directly. My understanding is that StarTech.com UKcarries Micro SATA Cablesproducts, so you could try there as well...